Author/Authors :
harun, zambri universiti kebangsaan malaysia - faculty of engineering built environment, Bangi, Malaysia , abbas, ashraf amer universiti kebangsaan malaysia - faculty of engineering built environment, Bangi, Malaysia , nugroho, bagus university of southampton - aerodynamics and flight mechanics group, Southampton, uk , nugroho, bagus university of melbourne - department of mechanical engineering, Victoria, Australia , chan, leon universiti tenaga nasional - department of mechanical engineering, Kajang, Malaysia , mat, sohif niversiti kebangsaan malaysia - solar energy research institute (seri), Bangi, Malaysia
Abstract :
Aerodynamic and skin friction effects are two main factors determining fuel efficiencies in the transportation industry. In any of transportation areas, either road transport, railway, maritime or aerospace, fuel efficiency has become interesting and sometimes sensitive topics. Data were from experimental studies, simulations as well as news and discussions in engineering bulletinsdanfuel efficiency, i. e. skin friction. Studies in skin friction are very important because skin friction drag account the majority of drag in a streamlined body e. g. tankers. The use of biomimetic, i. e. the study of the structures and functions of biological systems in the design of engineering systems has attracted a lot of attentions in the last few decades. Mimicking the arrangement and pattern on shark scales and how owls quietly fly has contributed to progress in various engineering fields. Simulation works are carried out especially to reduce costs and to obtain estimation of drags prior to experiment works. However, current computational resources only allow turbulent flows to be simulated at low and medium Reynolds numbers -far below that of engineering flows. This has lead researchers to develop empirical models which can be used for practical engineering applications so that engineers are able to obtain a estimate of the drag on the surface. Throughout the years, many models have been proposed but none has been universally reliable. Indeed, the turbulent flow over rough surfaces is a complex field of research and much is still to be discovered.
